As a Papillion, NE orthodontist, Dr. Nathan Hawley specializes in diagnosing, preventing and treating malocclusion. Malocclusion is doctor-speak for a “bad bite,” meaning the upper and lower teeth don’t come together correctly because of a dental or skeletal irregularity.
Today, we’ll be comparing two types of malocclusion: underbite vs. overbite. The Hawley Orthodontics team will cover what these bite problems are, what causes them, the complications they can lead to and how they’re treated. Let’s do this!
Underbite vs. Overbite
The main difference between an overbite vs. underbite lies in whether the upper or lower teeth and jaw are involved. With both types of malocclusion, one arch of teeth is too far in front of the opposite arch of teeth, often due to a discrepancy in jaw growth.
What is an Underbite?
When a patient has an underbite, the lower jaw is forward in comparison to the upper jaw and the lower front teeth sit outside of the upper teeth. Underbites tend to be skeletal in nature. That means the problem is related to jaw growth, most commonly a too large lower jaw or too small upper jaw.
Underbite vs. Crossbite
Underbites and crossbites both entail the bottom teeth biting in front of the top teeth. With a crossbite, one or more lower teeth are in front of the upper teeth either in the back of the mouth (posterior crossbite) or the front of the mouth (anterior crossbite). However, with an underbite, the entire lower jaw is forward.
What is an Overbite?
Overbite is the term for the amount that the upper front teeth vertically overlap the lower front teeth. A little bit of an overbite is completely normal. If the upper front teeth didn’t slightly overlap the bottom teeth, they would hit each other whenever you bit down, leading to premature wear of the enamel. A complete lack of an overbite is actually its own problem, called an open bite.
When the degree of overlap is too large, however, it’s considered an excessive overbite, also referred to as a deep bite. An excessive overbite can be dental (caused by the position of the teeth) or skeletal (due to the shape or size of the jaw). In extreme cases, the bottom teeth can even bite into the roof of the mouth.
Overbite vs. Overjet
People often use overbite and overjet interchangeably, and though you can have both problems simultaneously, they’re two different types of malocclusion. While an overbite refers to the degree of vertical overlap, overjet refers to the horizontal distance between the top and bottom front teeth. When a patient has overjet teeth, their top front teeth protrude or flare out over the bottom teeth – i.e., buck teeth.
What Causes an Underbite?
Most underbites are genetic and develop based on the dental and skeletal traits you inherit from your parents. It can be because the upper jaw didn’t grow enough, the lower jaw grew too much or a combination of both.
Other causes of an underbite include:
- Oral and myofunctional habits, including tongue thrust, prolonged pacifier use or thumb sucking, that interfere with jaw growth
- Jaw or facial trauma
- Jawbone tumors
- Birth defects, such as cleft lip and palate
What Causes an Overbite?
An excessive overbite is commonly caused by a lower jaw that is too small. Again, this is genetic, which unfortunately means that most of the time a deep bite can’t be prevented. Because the lower jaw is smaller than the upper jaw, the top teeth are positioned further forward and cover too much of the lower teeth.
An overbite can also be caused by:
- Overused chewing muscles from habits like chronic teeth grinding and clenching, or bruxism
- Missing lower back teeth, which can cause the bite to collapse
What Complications Can an Untreated Underbite Cause?
If not treated, an underbite can cause:
Difficulty biting and chewing
- Jaw and temporomandibular joint (TMJ) pain and dysfunction
- Increased risk of trauma to lower teeth if the bottom teeth stick out
- Speech issues
- Mouth breathing
- Sleep-disordered breathing, such as sleep apnea
- Uneven wear of the enamel
- Increased risk of tooth decay and gum disease since misaligned teeth are harder to keep clean
- Cosmetic concerns, such as a “bulldog” appearance with a protruding lower jaw
What Complications Can an Untreated Overbite Cause?
An excessive overbite can lead to:
- Trauma to the front teeth
- Excessive and/or uneven wear of the enamel
- Speech difficulties
- Problems biting and chewing
- Gum and soft tissue damage around the teeth
- Jaw and temporomandibular joint (TMJ) pain and dysfunction
- Increased risk of tooth decay and gum disease
- Sores or painful ulcers if the lower teeth hit the sensitive soft tissues behind the top teeth
- Airway obstruction and sleep-disordered breathing
- Cosmetic concerns, including a “weak” or receded chin
How to Fix an Underbite
When determining how to fix an underbite, Dr. Hawley takes the patient’s age and the severity of their case into account. Options might include:
Phase 1 Orthodontic Treatment
Since an underbite is a fairly easy condition to spot, the good news is, parents often seek treatment for their child early on. Underbites tend to be skeletal and the earlier the condition is diagnosed, the more likely it is we can treat it non-surgically.
While we treat kids conservatively here at Hawley Orthodontics, there are times when early interceptive orthodontic treatment, or phase 1 orthodontic treatment, is the best route.
With phase 1 orthodontic treatment, Dr. Hawley uses an orthodontic appliance to modify the growth of your child’s jaw while they’re still developing. While the specific appliance used will depend on your child’s unique anatomy and the cause of the underbite, we could recommend a palatal expander or other device to expand the upper jaw and encourage it to grow forward, eliminating the underbite.
Dr. Hawley always aims to finish phase 1 treatment in 12 months or less. Once the phase 1 goals are achieved, your child will have a resting period where we let the remainder of the permanent teeth come in naturally. They’ll continue to come in for growth and development check-ups, so Dr. Hawley can pinpoint the best time to begin phase 2 orthodontic treatment. During phase 2, he’ll use braces or Invisalign® Teen to straighten the teeth and finetune the bite.
Phase 1 orthodontic treatment for an underbite can make later treatment much easier, faster and more affordable. It can also help your child avoid the need for corrective jaw surgery when they’re older.
A lot of patients respond well to braces for underbite correction. For a mild underbite in someone who is still growing, we might use braces and rubber bands. The braces straighten the teeth in each arch, while the rubber bands, which connect to the upper and lower teeth, provide the connective force needed to shift the top arch forward and lower arch back.
A moderate underbite might require other temporary devices in conjunction with braces, so we can achieve more complex tooth movements and safely generate the force needed to align the bite. Rarely, teeth may need to be extracted. After they’re extracted, the spaces are closed with braces.
Can Invisalign fix an underbite? Yes, we can fix an underbite with Invisalign treatment in some cases. Just like with braces, we’ll need a connective force to create the ideal relationship between the upper and lower teeth, so we may use Invisalign rubber bands with the aligners. You’ll also have Invisalign attachments, which are tooth-colored buttons, bonded to your teeth to give the aligners something to push off of for more leverage.
Treating a severe underbite in an adult patient is more difficult than correcting the problem in childhood or the teen years when the jaw is growing. Some patients will get the best results with surgical orthodontics, which is when we combine orthodontic treatment with orthognathic surgery (corrective jaw surgery).
Though we can address more cases than ever before without jaw surgery, there are times when it’s needed. With this approach, Dr. Hawley will work closely with your oral surgeon. You’ll get braces or Invisalign for a period to shift the teeth where they need to be. Then, you’ll undergo corrective jaw surgery to realign the jaw. After a healing period, you’ll have one more round of orthodontic treatment to make any final tooth movements and create a strong, stable bite.
How to Fix an Overbite
Sometimes, an excessive overbite doesn’t cause major aesthetic issues and people don’t realize they have one until they visit the orthodontist for another problem like crowding. This is why the American Association of Orthodontists recommends kids have their first orthodontic assessment by age 7. At this point, Dr. Hawley can spot subtle problems like an emerging overbite and either monitor it until the time is right for treatment or, in severe cases, intervene early.
The exact course of treatment to fix an overbite will depend on how severe the problem is and whether it’s caused by an irregularity in jaw growth. Options may include:
Phase 1 Orthodontic Treatment
Not all cases of an overbite, or deep bite, require phase 1 orthodontic treatment. But, when it is necessary, early interceptive orthodontics allows Dr. Hawley to guide jaw growth with an orthodontic appliance. During phase 1 treatment, Dr. Hawley fixes the discrepancy in size between the upper and lower jaw that’s causing the overbite. This can help your child steer clear of corrective jaw surgery, extractions or complex treatment later in life.
After a resting period, where we simply monitor your child, they’ll start phase 2 orthodontic treatment. Dr. Hawley will straighten their teeth and perfect their bite using braces or Invisalign Teen.
Braces are a great option for fixing an overbite. While some patients might respond to braces alone, most commonly, when correcting an overbite, braces are combined with rubber bands or another appliance. The braces shift the teeth while the rubber bands or appliance help to open the bite by advancing the lower jaw and creating a harmonious relationship between the upper and lower teeth.
Invisalign can fix an overbite as well. Dr. Hawley will usually pair the aligners with Invisalign attachments and rubber bands. This helps align the bite while straightening the teeth.
Additionally, with innovations like Invisalign with Mandibular Advancement (MA), correcting an overbite in teens with aligners is more effective than ever. The aligners have precision wings that engage when the patient bites down. This advances the lower jaw forward bit by bit until it’s in harmony with the upper jaw.
Overbite surgery is becoming increasingly less common, but it’s still used for adult patients with a severe overbite that significantly interferes with function and aesthetics. The multi-step process involves getting braces or Invisalign, followed by corrective jaw surgery performed by an oral surgeon. Once the jaw heals, we finish up by using braces or Invisalign again to make any final adjustments.
Find Out Your Options for Underbite and Overbite Correction in Omaha, NE
If you have an underbite or overbite, schedule a complementary consultation with our Papillion orthodontist, Dr. Hawley. At Hawley Orthodontics, our team uses the latest technology and treatments to help patients get amazing results more efficiently and comfortably.